A diagnostic test which allows multiple examinations of more than 1,000 genetic diseases in the foetus

Next-generation Genomics and Prenatal Diagnosis

The extraordinary advances in the genomic and biotechnology sectors in the past few years paved the way for reading and understanding information on the foetal genome. Notably, new sequencing technologies called Next Generation Sequencing (NGS) make the analysis of DNA sequences easier and more effective, thus providing in-depth genetic information of the foetus.

About PrenatalScreen®

PrenatalScreen®
is a diagnostic test developed by the
GENOMA Group which allows multiple examinations of more than 1,000 genetic diseases in the foetus, including the most common in the Italian population, such as Cystic Fibrosis, Sickle Cell Anaemia, Thalassaemia, Spinal Muscular Atrophy and Hereditary Deafness. PrenatalScreen®
allows expectant mothers to know whether their child suffers from severe genetic diseases through foetal DNA analysis.

PrenatalScreen®
is suggested in the following cases:
• Personal/familial anamnesis of hereditary genetic diseases;
• For expectant mothers wanting to reduce the risk of a genetic diseases in the foetus;
• For natural pregnancies as well as medically assisted procreation procedures (MAP);
• For couples using heterologus artificial insemination procedures.

PrenatalScreen®
analyses DNA extracted from foetal cells in the amniotic fluid, collected through amniocentesis, or in the chorionic villi through villocentesis. The aim of this diagnositc test is to study severe genetic diseases in the foetus, including the most frequently occuring diseases in the Italian population. Genes listed in Table 1 were selected according to the percentage of diseases caused by mutation to such genes occurring in the population, the severity of the clinical phenotype at birth and the importance of the related pathogenetic picture in accordance with the indications of the American College of Medical Genetics (ACMG)(Grody et al., Genet Med 2013:15:482–483).

Procedure

PrenatalScreen®
test on the amniotic fluid is done via an ultrasound-guided transabdominal aspiration of 15-20 ml of amniotic fluid, between the 15th and the 18th week of pregnancy. The centrifugation of the amniotic fluid separates the liquid portion from the mass fraction which includes foetal cells suspended in the amniotic fluid. From such cells, called amniocytes, DNA is extracted.
The PrenatalScreen® on chorionic villi is carried out by ultrasound-guided transabdominal collection of around 20 mg of chorionic villi between the 11th and the 13th week of pregnancy. The collected material is washed and observed under the microscope to separate the maternal tissue from the foetal tissue. Then DNA is extracted.
The DNA isolated from the foetal cells is then amplified through PCR. Through a state-of-the-art technological process called
massive parallel sequencing (MPS), which uses
Next Generation Sequencing (NGS) techniques with
ILLUMINA sequencing instruments,
744 genes are completely sequenced (exons and adjacent intrionic regions, ± 5 nucleotides) (Table 1) at high read depth. The resulting genetic sequences are analysed via an
advanced bioinformatics analysis, to check the presence of potential mutations in the examined genes.

Accuracy

Present DNA sequencing techniques are more than 99% accurate. Even though this test is very accurate, the limitations of this examination are to be always taken into consideration. Please read below.

Limitation of the PrenatalScreen® test

Present DNA sequencing techniques are more than 99% accurate. Even though this test is very accurate, the limitations of this examination are to be always taken into consideration. Please read below.

A “NEGATIVE” - No mutations result for the examined genes does not exclude the possibility that mutations are present in a region of the genome that was not explored during the examination.
Some regions of our DNA may not be sequenced or have a lower coverage than the limitations set by GENOMA Group experts to guarantee an accurate examination of gene variations. These regions, therefore, are not included in the examination if they do not meet the requested qualitative standards.

Results

“POSITIVE“
– Presence of one or more mutations: this result shows that the test detected one or more mutations in one or more genes. Our geneticist will explain the meaning of the test results in detail during the genetic consulting phase and, if needed, will communicate the need to make further examinations on the parents in order to check whether the detected mutation is hereditary.
Mutations detectable through the PrenatalScreen® test may be classified under the following prognosis categories:

A) with known prognostic outcome; ;
B) with benign outcome since they may be detected in healthy individuals and are not associated with any pathological outcome;
C) with uncertain outcome since they are not yet known or classified by the medical and scientific community.

“NEGATIVE”No mutations: this result shows the test has not detected any mutations in the examined genes. Such result significantly reduces the probability that the foetus carries the examined genetic diseases, although no guarantee may be given that the foetus is actually healthy

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About us

GENOMA: a rich heritage combining technologies and
people, a model for quality, professional expertise and
competencies.

GENOMA is a highly specialised
diagnostic centre in Italy, renowned for its
contribution to the advancement of molecular
diagnostics. The laboratory is also renowned
internationally thanks to its collaboration with
scientific networks and prestigious research projects.

GENOMA, incorporated in 1997, is the point of
reference for high-tech examinations. It is mainly a
"service" centre for highly specialised prenatal and
postnatal genetic, cytogenetic and molecular
examinations.

GENOMA is considered as one of the most
advanced molecular diagnostics centre in Europe and its
head offices are in Rome and Milan. The laboratories are
in a modern, high-tech building and cover a surface of
more than 4,000 sqm. The centre uses state-of-the-art
instruments and technologies and works at high quality
levels.

GENOMA professionals have been working in
genetics for more than 20 years. A team of more than 100
professionals, including geneticists, molecular
biologists, gynaecologists, researches and laboratory
technicians work together operating in the field of
cytogenetic and molecular diagnostics for clinical
applications and research and are led by Dr. Francesco
Fiorentino inside a centre with very high technical and
scientific standards.

GENOMA works all over Italy
and abroad in Europe, the United States and the Middle
East, providing specialised diagnostic support for
public and private health clinics, examination
laboratories, health centres, hospitals, private
clinics, general outpatients' clinics, medically
assisted procreation centres and physicians specialising
in different fields. Our laboratories receive
biological samples from more than 5,000 health centres
and hospitals every day. The integrated approach of the
Centre is aimed at performing extremely high volumes of
examinations; more than 100,000 genetic tests,
constantly increasing, are carried out every year.

One of the features of the Group is a well-organised
network of services, one of the most comprehensive in
Italy and abroad, allowing the centre to offer its
patients and their physicians innovative diagnostic
solutions for any clinical need. With a list of more
than 1,500 genetic tests available directly in our
laboratories and divided into 20 areas of application,
GENOMA is able to meet increasingly specialised requests
in cytogenetic and molecular diagnostics, providing its
customers with a highly specialised, precise, effective
and rapid service.

GENOMA is a laboratory with one
of the longest, wide-ranging experience in Europe in
prenatal diagnostics. Thanks to this heritage, the Group
can offer expectant mothers and their physicians
state-of-the art technologies for foetal chromosome and
genetic diseases diagnostics.